Regulation of lipoprotein lipase gene expression by insulin and troglitazone in rainbow trout (Oncorhynchus mykiss) adipocyte cells in culture.

Adipose tissue plays a central role regulating the balance between deposition and mobilization of lipid reserves. Lipoprotein lipase (LPL) is a key enzyme controlling lipid accumulation in mammals and fish. In the present study, we have examined the expression of LPL in rainbow trout cultured adipocytes and we have investigated the effect of troglitazone, a member of thiazolidinediones (TZDs), and insulin on its expression. LPL gene expression increased from day 1 until day 12 of culture, and the level was maintained up to day 21. The addition of insulin at 10 nM and 1.7 µM increased significantly LPL gene expression in undifferentiated cells (days 7 to 12 maintained in growth medium). Nevertheless, treatment of day 7 cells incubated in growth medium with troglitazone (5 µM) or troglitazone plus insulin (1 µM each), tended to enhance LPL expression. In addition, LPL mRNA levels increased significantly in the presence of 1 µM and 5 µM of troglitazone (days 7 to 12) when the cells were induced to differentiate by addition of differentiation medium. Although troglitazone alone (1 µM) did not stimulate lipid accumulation in the cells neither in growth nor in differentiation medium, the simultaneous presence of troglitazone (1 µM) and insulin (1 µM) increased significantly the content of triglycerides in adipocyte cells maintained in growth medium (days 7 to 12). These results indicate that insulin and troglitazone regulate LPL gene expression during adipocyte differentiation and suggest that both factors may have combined effects in the modulation of adipogenesis.

Insulin and insulin-like growth factor I signaling pathways in rainbow trout (Oncorhynchus mykiss) during adipogenesis and their implication in glucose uptake.

Primary cultures of rainbow trout (Oncorhynchus mykiss) adipocytes were used to examine the main signaling pathways of insulin and insulin-like growth factor I (IGF-I) during adipogenesis. We first determined the presence of IGF-I receptors (IGF-IR) and insulin receptors (IR) in trout preadipocytes (day 5) and adipocytes (day 14). IGF-IRs were more abundant and appeared to be in higher levels in differentiated cells than in preadipocytes, whereas IRs were detected in lower but constant levels throughout the culture. The cells were immunoreactive against ERK1/2 MAPK, and AKT/PI3K, components of the two main signal transduction pathways for insulin and IGF-I receptors. Stimulation of MAPK phosphorylation by IGF-I was higher in preadipocytes than in adipocytes, while no effects were observed in MAPK phosphorylation after incubation of cells with insulin. AKT phosphorylation increased in the presence of both insulin and IGF-I, with higher levels of stimulation in adipocytes than in preadipocytes. Activation of both pathways was blocked by the use of specific inhibitors of MAPK (PD98059) and AKT (wortmannin). We describe here, for the first time, the effects of IGF-I and insulin on 2-deoxyglucose uptake in primary culture of trout adipocytes. IGF-I was more potent in stimulating glucose uptake than insulin, and PD98059 and wortmannin inhibited the stimulation of glucose uptake by this growth factor, suggesting that IGF-I plays an important metabolic role in trout adipocytes. Our results suggest that differential activation of the MAPK and AKT pathways are involved in the IGF-I- and insulin-induced effects of trout adipocytes during the various stages of adipogenesis.

[Pertussis: data collection and vaccinal strategy]. / La coqueluche : collecte de données et choix des stratégies vaccinales.

UNLABELLED: Renacoq is a pediatric hospital-based surveillance network in France, set up in April 1996 to monitor the trend of pertussis among children and the impact of vaccination strategies. METHOD: The authors studied the link between data collection and public health policy. Microbiologists from 43 hospitals notify diagnosis of pertussis among children less than 16 years of age. Pediatricians complete a questionnaire for infants less than 6 months of age fulfilling the case definitions. Positive cultures are sent to the National reference laboratory to validate biological results. Data collected from 1996 to 2007 was analyzed, as well as its interaction with changes in pertussis vaccine policy. RESULTS: The introduction of adolescent and adult boosters was largely supported by Renacoq data but this was not the case for interruption of whole cell vaccine use. The impact of adolescent booster is moderate because of a limited vaccine coverage. There was no observed impact of the adult booster but the coverage is very weak. The introduction and then the sole use of acellular vaccine did not have any impact on Renacoq data. DISCUSSION: The study illustrates the burden of the disease among infants and the link between surveillance data collection and public health decision. It highlights the difficulty to implement new vaccine strategies and the importance of data collection, stressing the need for a better consideration of hospital practitioners involved in public healthcare surveillance.

Regulation of proliferation and differentiation of adipocyte precursor cells in rainbow trout (Oncorhynchus mykiss).

Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor alpha (TNFalpha) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator-activator receptor gamma, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFalpha on the differentiation of these adipocytes in primary culture. TNFalpha inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.

[Conductive disorders following open-heart valvular surgery. Concerning 230 operated patients]. / Les troubles conductifs après chirurgie cardiaque valvulaire sous circulation extracorporelle. A propos de 230 malades opérés.

AIMS: Conductive disorders following open-heart valvular surgery represent serious complications that may require definitive pacemaker implantation. The natural history of these troubles is not well established thus, controversy persist concerning the timing of pacemaker implantation. In this study we identify the predictive factors of permanent conductive disorders in order to assess the optimal time of pacing. METHODS AND RESULTS: Two hundred thirty valvular replacements were done between 1993 and 2003. The mean age of our patients was 42 +/- 13.4 years. Rheumatic valvulopathies accounted for 76% of cases, with 54% of multiple valvulopathies. Twenty-two patients (9,5%) had an early postoperative conductive disorder, 9 of them (4%) were definitively implanted after a mean delay of 31.8 days. Preoperative bifascicular bloc and early installation of postoperative high-grade conduction disturbances and its persistence for more than 48 hours are significantly associated with permanent postoperative conductive disorders (respectively P = 0.04 and = 0.03). Aortic valve surgery and infective endocarditis were more frequent in the implanted group but the difference was not significant. CONCLUSION: After open-heart valvular surgery; predictive factors of definitive conductive troubles justify an earlier pacemaker implantation. This attitude may accelerate the hospital discharge and decrease the disease cost effectiveness.

[Prognostic significance of second and third degree atrioventricular block in acute inferior wall myocardial infarction]. / Valeur pronostique du bloc auriculoventriculaire du deuxième et du troisième degré au cours de la phase aiguë de l'infarctus du myocarde inférieur.

High degree atrioventricular block complicates inferior wall acute myocardial infarction in 10 to 15% of cases. Its significance is still controversial. In this study, we have analysed 152 observations of acute inferior wall myocardial infarction during hospitalisation period. The mean age of our patients is 60 years, 48.7% of them have received fibrinolytic treatment. Second or third degree atrioventricular block was detected in 33 cases (21.7%). Mortality is higher in inferior wall myocardial infarctions with atrioventricular block than in those without atrioventricular block (12% versus 2.5%, p < 0.05). Hemodynamic complications like cardiogenic shock due to the extension of the infarction to the right ventricle and left ventricle insufficiency are more frequent (18% versus 3.4%, p < 0.01 and 12% versus 3.5%, p < 0.01 respectively). It appears that the infracted mass of myocardium is larger in case of atrioventricular block, this is assessed by comparing the average value of the peak of creatine Kinase in the two groups with and without atrioventricular block (1534 IU versus 1096 IU, p < 0.02) and by considering the rate of low ejection fraction (EF < 40%) in each group (44.6% versus 16%, p < 0.01). In our study, we note that thrombolysis does not affect the incidence of atrioventricular block (19% and 24% in thrombolyed and not thrombolyzed patients respectively) but it seems that thrombolysis improves the outcome of these patients. The occurrence of atrioventricular block in acute inferior wall myocardial infarction is related to the presence of an important right coronary artery that is occluded, the recanalisation of this vessel leads often to rapid regression of the block that is no longer pejorative.

[Correlation between aortic atherosclerosis at transesophageal echocardiography and coronary atherosclerosis]. / Corrélations entre l'athérosclérose aortique à l'échocardiographie transoesophagienne et l'athérosclérose coronaire.

The aim of this study was to test the relationship between atherosclerotic plaques in the thoracic aorta detected by transesophageal echocardiography and coronary artery disease detected by angiography. A prospective study was carried out in 103 patients who underwent coronary angiography. All patients underwent transesophageal echocardiography with imaging of the thoracic aorta. Aortic intimal changes were classified in 4 grades. The detection of aortic atheroma plaques was the strongest predictor of coronary artery disease. The presence of aortic plaques on transesophageal study had a sensitivity of 97.6% and a specificity of 80% for angiographically proved obstructive coronary artery disease. The positive predictive value of aortic plaque for obstructive coronary artery disease was 95.3% and the negative predictive value was 88.9%. Compared to the other segments, the detection of atherosclerotic plaque in the descending aorta has the highest sensitivity but the specificity was the highest in the ascending aorta. With older age and in women the specificity decreased, while the sensitivity increased.

[Assessment of pure isolated mitral valve insufficiency by Doppler echocardiography]. / Quantification des insuffisances mitrales pures isolees par l'echodoppler cardiaque.

Taking 33 patients having pure MI as a material, the authors find a correlation between regurgitation fraction obtained by calculation of outputs estimated by Touch's method and angiographic values. There is a statistically significant differences (P < 0.001) between regurgitation fraction of grade I to II and grade II to III MI. The ratio mitral integral time velocity (ITV) to Aortic (ITV) is an important semi-quantitative assessment of pure MI. In fact, a ratio > 1.3 identify important degree of MI with 82% sensitivity and 93% specificity. The authors estimate that there is a correlation between the ratio of regurgitant jet surface to left atrial surface found in TEE and their degree of MI in angiography with a significant difference (P < 0.001) between the ratio of grade I to II and grade II to III MI in angiography. A ratio higher than 40% allow to identify grade III MI at minimum.

[Assessment of the quality of management of arterial hypertension in a public health center (Ariana - Tunisia)]. / Evaluation de la qualité de la prise en charge de l'hypertension artérielle dans un centre de santé de base public (Ariana-Tunis).

The management of hypertensive outpatients in a primary health care center raises problems of follow-up and effectiveness. This study attempts to assess the management of high blood pressure, using the Medical Audit method, essentially. For that purpose, 194 medical records of hypertensive outpatients registered between 1980 and 1986 were studied. More than 80% of these patients were women between the ages of 40 and 70 years. The medical records of these patients were compared to a standard management scale including 68 items devised by cardiologists and general practitioners. Globally, 32% of the items were cardiologists and general practitioners. Globally, 32% of the items were respected during management of the outpatients. The initial check-up was the least followed item (6.9%), but afterwards care of patients improved, giving ratings of: 29% for respect of treatment protocol, and 35% for surveillance of treatment. As concerns treatment effectiveness, only 28% of the patients (n = 36) actually completed the five-year follow-up period. In these patients average blood pressure fell from 193 to 143 mmHg (systolic), and from 113 to 93 mmHg (diastolic), between the beginning of monitoring and the end of the fifth year. The insufficiency of high blood pressure management results not only from a shortage of resources, but also from underuse of existing ones, and the practitioners' lack of information.